Manhole cover



Feb. 28, 1933; o. N. GREDELL MANHOLE COVER Filed March 15, 1930 INVENTOR 0/ 0 .6/730 6 ATTORNEY Patented Feb. 28, 1933 UNITE STATES PATENT oiFFIc-E OTTO N. GREDELL, OF KANSAS CITY, MISSOURI, ASSIGNOR TOSTANDARI) STEEL WORKS,

OF NORTH KANSAS CITY, MISSOURI, A CORPORATION OF MISSOURI MANHOLE COVER Application filed March 15, 1930. Serial No. 436,092

My invention relates to manhole and like covers for closing openings 1n containers such as tanks.

A manhole cover must be adapted to afford access to the tank on which it is mounted, for introducing or withdrawingliquid, cleaning the tank, inspecting the interior, and similar purposes, and when the contained liquid is relatively volatile, the cover when closed must securely seal the manhole opening to preventescape of gases. The

production of an eflicient seal is usually 210- I tunityfor applying'only one lever for rotat-i mg a cover.

The principal objects of my: invention therefore are 'to facilitate application and removal of a manhole cover, to obviate hazard of breakage of cover partswhen a screwthreaded cover is rotated for application or removal, to form means within'acover to receive a'tool for removing the cover, to reenforce tool-receiving means on a cover, to reenforce the portions of a tank that receive a cover, and to adapt a cover for insertion of a lever thereinto for rotating the cover.

In accomplishing these and other objects of the invention, I have provided-improved details of structure, the preferred forms of which are illustrated in the accompanying drawing, wherein: Y i i 1 r Fig. 1 is a perspective view of a portion of neath of a portion of the cover including the removal of a cover may be rendered difiicult V a tank provided with my improved manhole reenforced inner end of a lever socket'projecting into the cover. I -Referring in detail to the drawing:. 7

'1 designates a portion of the upper metal wall of a liquid container such as a truck tank in which a manhole opening isformed. A dome-like cover member 2 mounted in the opening includes a tubular skirtiportion 3 having a circular periphery engaging the inner edge of the tank wall at theopening and fixed to the wall by suitable means'such as welding 4=,"the skirt projecting downwardly into the tank to provide extensions which may receive lower or inner welds 5.

The dome has a relatively large axialopening formed by an inwardly extending sub-' stantially horizontal portion 6 thereof, and outer and inner flanges 7 and 'S'BXfQHd at right angles to said portion to form a ringlike inner periphery for the dome having substantial'vertical width. a

An internally threaded-ring 9 preferably of brass having exterior'protuberanoes such as a rib 10, may be incorporated with the dome member upon construction thereof, preferably by casting the dome member to form: the flanges 7 and 8 around the outer p'eripheryof the ring, whereby the rib lO-is embedded in the-rim of the domemember around the axial opening thereof. The rib '10 preferably is adapted to form an annular groove '11 on the median line of the faceof; said dome rim having an upper wall 12 inclined slightly'downwardly inwardly to the median line of the portion 6,and'a' lower wall 13 substantially at rightyangles' to the wall' 12, whereby the ring is securely retained to receive a covercmember 14 adapted to be easily applied for closing-the manhole opening or to be removed for affording access to the tank for cleaning or the like.

The member'li comprises an arcuate cas a ing having-a depending threaded flange '15 ,c inwardly ofl'set from the margin thereof to engage the ring 9'and form a shoulder 16 adapted to seat on the registering upper edges of the flange 8 and ring 9, the inner I circular wall 17- of' the casing defining a re rounding the opening 33 exteriorly to said cross section and having axes extending radially to the axis of the casing, the inner ends of the sockets being closed by stop walls 19 and the open outer ends registering with openings 20 in the body of the member to admit a suitable lever 21 for effecting rotation of the member.

In order to reenforce the sockets and cover member to resist strains due to operation of the lever, ribs or wings 22 and 23 en a e the a A o c inner Wall of the cover member and the slde walls of the sockets, and are preferably formed integrally with the members with which they are engaged.

The cover wall 24 of the casing is provided with a central opening, and has flanges 25 and 26 and a groove 27 similar to the flanges 7 and 8 and groove of the dome member 2, and a ribbed brass ring 28 is fixed against rotation on the circular edge of the wall 24 around the opening therein, to receive the threaded skirt or flange 29 of a second removable cover member or cap 30 having a recess 31 and a cover wall 32 provided with acentral opening 33 surrounded by a thickened wall portion 34 and normally closed by a threaded plug 35.

The ring 28 is preferably installed by casting or moulding thecover wall 24 around the ring to embed the rib thereof in the edge of the wall.

A tubular boss or chamber wall 36 surportion 34 depends through the recess 31 in the cap 30 into the recess of the casing 14, and is provided with an internal annular groove 37 and a projecting annular flange 38 below the groove to receive and support a relatively fine mesh copper fire screen 39 mounted on a spring wire ring 40.

A spider-like transverse bar 41 secured to the lower edge of the boss has an opening to receive a swivel pin 42 having an eye 43 and a chain 44 having one end mounted in said eye is fixed to a lug 45 on the inner face of the cover wall 24 of the casing 14 for providing a flexible connection between the cap and casing, whereby loss of the cap will be avoided when the same is removed for inspection of the tank or the like.

Levers 46 having vertical end spacing portions 47 fixed to the cap adjacent the plug provide fixed means for rotating the cap to apply or remove the same, and also form guards'for the plug.

In use the arcuate cover support fixed to the tank forms an expansion dome extending substantially above the top of the tank, the arcuate removable cover members contributing to the volume of the dome, and being elevated above the tank for convenient application of levers for removal of the The cap may be easily removed by application of force to the fixed lever handles, and will be retained in connection with the cover casing 14 by the chain.

The cover casing 14 may be rotated by levers inserted in the sockets, and any requisite amount of force may be appliedforsecuring the cover in the opening or removmg it therefrom, since the reenforced sockets are capable of resisting severe strains, and strains are transmitted to the relatively heavy skirt portion of the casing.

Attention is called to the merging of the surface of the dome member 2 into the smooth curved surface of the cover 14, whereby a cover is provided that-forms a symmetrical crown for the dome, and aflords opportunity for forming the laterally directed openings of the sockets to admit the levers. The sockets may thus be located at the lower end of the cover adjacent the threaded flange, whereby the pressure of the levers will be applied close to the threaded joint, and the levers will move substantially in the horizontal plane of the base of the cover. The reenforcing internal ribs will receive the lateral pressure of the inner ends of the levers.

The outer ends or mouths of the sockets are flush with the arcuate surface of the cover, and the socket walls thus provide reenforced lever-receiving abutments or plates to anchor the inner ends ofthe levers, said abutments being recessed within the cover and offering no projections exterior to the dome.

A plurality of levers may be applied to several sockets coinci-dently, for removing a cover; 1

7 What I claim and desire to secure by Letters Patent is:

1. In a device of the character described, a recessed cover having a depending threaded flange and a laterally directed lever-receivthe recess for anchoring the inner end of a lever adapted to be inserted in the aperture for rotating the cover.

2. In a device of the character described,

forming a recess, a socket member mounted in said recess havlng an open end registering with the aperture in sald wall, and a rib fixed receive a lever for rotating the cover, and

ing aperture, and means fixed to said cover in :a cover member having an ap-ertured wall tosaid socket and said wall for bracing the means including abutments in said cover in alignment with the edges of said aperture for receiving lateral pressure of the lever.

4. In a device of the character described, a

convexly curved cover member having a depending circumferential flange forming a recess and for securing the cover to a manhole, and a socket member in the recess having a closed rectangular shaped socket'opening through the convex portion of the cover member adjacent its periphery to admit the end of a rectangular shaped bar for rotating the cover. I p g 5. In a device of the character described,

a dome having a convexly curved upper portion provided with a manhole opening, and a convexly shaped cover for the opening having a curved surface conforming substantial- 1y to the curvature of the dome and having inwardly extending sockets adjacent its lower edge to admit the end of a bar for removing w the cover from the dome.

In testimony whereof I aflix my'signature.

OTTO N. GREDELL. 

